CONTENTS

"TODESIGN AN APPROPRIATE
OR & AND LOGIC GATE FOR A
GIVEN TRUTH TABLE"
PAGE No.-2
.

RIGHT/WRONG.
TRUE/FALSE.
The logic gates are building blocks at digital electronics. It is a digital circuit
which either allows a signal to pass through as stop. CLOSED/OPEN. it is called a gate.
A logic gate may have one or more inputs. They are used in
digital electronics to change on voltage level (input voltage) into another
(output voltage) according to some logical statement relating them.
A logical statement can have only two values. The
relationship between the possible values of input and output voltage is
expressed in the form of a table called truth table or table of combinations. this algebra of logic called BOOLEAN ALGEBRA.-3
. but it has only one output. The
binary number 1 is used to denote the high value. YES/NO. INTRODUCTION
A gate is defined as a digital circuit which follows some logical
relationship between the input and output voltages. The logical statements
that logic gates follow are called Boolean expressions
PAGE No.
Truth table of a Logic Gates is a table that shows all the input and output
possibilities for the logic gate. CONDUCTING/NON-CONDUCTING etc.
George Boole in 1980 invented a different kind of algebra based on binary
nature at the logic. The two
values of logic statements one denoted by the binary number 1 and 0. such as HIGH/LOW.
ON/OFF.

fluids.-4
. Although these circuits may be complex. the OR gate
and the NOT gate. We have three
different types of logic gates . Any Boolean algebra operation
can be associated with inputs and outputs represent the statements
of Boolean algebra.
LOGIC STATES
1 0
HIGH LOW
+v -v
ON OFF
CLOSE OPEN
RIGHT WRONG
TRUE FALSE
YES NO
PAGE No.Logic gates or logic gate is an entity in electronics and mathematics
Boolean that turns one or more logic inputs to a logic output signal.These are the AND gate. they
may all be constructed from three basic devices. optical or even mechanical. but can also be built using the arrangement of
components that utilize the properties of electromagnetic (relay).
Logic gate is mainly implemented electronically using diodes or
transistors.

The AND gate has two or more inputs and one output.(a) THE OR GATE is a device that combines A with B to give Y as
the result. The logic
gate of OR gate with A and B input
and Y output is shown below:
In Boolean algebra. indicates Y equals A OR B.
The Boolean expression:
A+B=Y. The
logic gate of AND gate with A and B input and Y output is
shown below:
PAGE No.-5
.
The OR gate has two or more inputs and one output.
(b) THE AND GATE is a device that combines A with B to give Y
as the result. addition symbol (+) is referred as the OR.

indicates Y equals NOT A. indicates Y equals A AND B.B=Y. The Boolean expression:
A.
(c) THE NOT GATE is a device that inverts the inputs. The
Boolean expression:
Ã =Y. In Boolean algebra.) is referred
as the AND. The NOT
is a one input and one output.
PAGE No. bar symbol (_) is referred as the NOT. The logic gate of NOT gate with
A and Y output is shown below:
In Boolean algebra. multiplication sign (either x or.-6
.

Truth table for an OR gate
Input A Input B Output
false false false
false true true
true false true
true true true
Symbols
The symbols below can be used to represent an OR gate. If all of an OR gate's inputs are false. The output of an OR gate is true when one
or more of its inputs are true.OR Gate
An OR gate is a digital logic gate with two or more inputs and one output
that performs logical disjunction. then the
output of the OR gate is false.
The truth table for an OR gate with two inputs appears to the right. and one may preferred over the other in
your region of the world.
Live Example
PAGE No. There are multiple
international standards defined.-7
.

d) If switch A & B are closed then (A=1. hence Y=1.t.e. making use of two
diodes D1 and D2 as shown in the figure. voltage 5V in the
present case) corresponds to level 1.
c) If switch A closed B open then (A=1.
Components:
Two ideal p-n junction diode (D1 and D2). B=0) Lamp glow. B=1) Lamp glow.
earth. hence Y=1.
b) If Switch A open B closed then (A=0. B=1) Lamp glow.r. hence Y=0.
Here the negative terminal of the battery is grounded and corresponds to
the 0 level.
Input A Input B Output Y
Truth Table: 0
1
0
0
0
1
0 1 1
1 1 1
PAGE No. The output Y is voltage at C w. hence Y=1.-8
. B=0). and the positive terminal of the battery (i.
The following interference can be easily drawn from the working of
electrical circuit is:
a) If switch A & B are open lamp do not glow (A=0.
Theory and Construction:
An OR gate can be realize by the electronic circuit.Aim:
TO DESIGN AND SIMULATE THE OR GATE CIRCUIT.

Example
PAGE No.-9
. There are
multiple international standards defined. The output of an AND gate is true only
when all of the inputs are true.AND Gate
An AND gate is a digital logic gate with two or more inputs and one output
that performs logical conjunction.
Truth table for an AND gate
Input A Input B Output
false false false
false true false
true false false
true true true
Symbols
The symbols below can be used to represent an AND gate. and one may preferred over the
other in your region of the world. If one or more of an AND gate's inputs
are false.
The truth table for an AND gate with two inputs appears to the right. then the output of the AND gate is false.

Aim:TO DESIGN AND SIMULATE THE AND GATE CIRCUIT. and the positive terminal of the battery (i.-10
. B=1) then Lamp will not glow.
hence Y=0.
Here the negative terminal of the battery is grounded and corresponds to
the 0 level. a resistance R. voltage 5V in the
present case) corresponds to level 1.t.e. B=0) then lamp will not glow.
Theory and Construction:
An AND gate can be realize by the electronic circuit.
Components:
Two ideal p-n junction diode (D1 and D2).
1 0 0
d) If switch A & B both closed 0 1 0
(A=1. The resistance R is connected
to the positive terminal of a 5V battery permanently. B=0) then Lamp will not glow.
hence Y=0. B=1) then Lamp will glow. making use of
two diodes D1 and D2 as shown in the figure.r.
earth. 1 1 1
hence Y=1.
b) If Switch A closed & B open (A=1. The output Y is voltage at C w. Input A Input B Output Y
0 0 0
hence Y=0.
c) If switch A open & B closed
(A=0.
The following conclusions can be easily drawn from the working of electrical
circuit:
a) If both switches A&B are open (A=0.
Truth Table
PAGE No.

PAGE No.-11
. Conclusion
IC CONSISTS OF SOME LOGIC GATE
LOGIC GATE CAN USED TO CREATE MANY IC.

co.com
PAGE No. icbse. scribd. Bibliography
I would like to acknowledge the following sources through which I
obtained vital information which contributed in the completion of
this project:
I.-12
. wikipedia.com
II. slideshare.in
IV.org
III.